EN
Oestrus status without standing reflex is enumerated among the typical clinical signs of zearalenone mycotoxicosis in sexually immature gilts. The aim of the study was to assess the influence of a low dose of zearalenone applied per os for 7 days on the morphometric results of the organs of the reproductive system in sexually immature gilts that were and that were not subjected to ovariectomy. Zearalenone and α-zearalenole were determined in blood plasma with the common use of separation methods with the columns of immunological affinity and high performance liquid chromatography with fluorescent detection. Tissues of the reproductive system were taken directly after the slaughter (on day 8 of the experiment) for morphometric examinations. The study was carried out on twelve 4 months old gilts, at 38-45 kg of body weight. The results obtained showed that per os application of zearalenone at a dose of 200 µg /kg b.w. for 7 days evoked signs of apparent sexual readiness without standing reflex in gilts after ovariectomy and in physiologically efficient gilts. The level of α-zearalenole had been significantly increased and zearalenone had been noted in blood serum before these signs appeared. Double and triple enlargement of the uterus was noted in both experimental groups. The mass and volume of the ovaries in physiologically efficient gilts diminished about 50%.